Cyclone separator



Aug. 19, 1952 B. E. BAILEY 2,607,438

' CYCLONE SEPARATOR Filed June 30, 1948 4 Sheets-Sheet l t PGAS OUTLETGAS To -41. '4 JETs 4 25 5 g v GAS AND Souos INLET Soubs :bradfor'd6.bai leg firm enter V Clbborrzg I Aug. 19, 1952 B. E. BAILEY 2,607,438

' CYCLONE SEPARATOR Filed June 30, 1948 4 Sheets-Sheet 2 GAS AND SousaINLET braclforcl 5. baile tf Urzverltf Clbborneg Aug. 19, 1952 B. E.BAILEY CYCLONE SEPARATOR Filed June 30, 1948 4 Sheet s-Sheet 5 FIfS 1 FI G bradford bazleg Jrzverzbor' clbborn egg- 4 Shets-Sheet 4 FIG-5 B. E.BAILEY CYCLONE-SEPQRATOR Ail 19, 1952 Fiiljed June so, 1948 r w w mm 5m.M a d w a Z r. b

Patented Aug. 19, 195i CYCLONE SEPARATOR Bradford 1 E. Bailey,'-Elizabeth, N. J as'signor to Standard Oil Development Company, acorporation of Delaware Application June 30, 1948, Serial No. 36,179

' 3 Claims.

This invention relates to improvements in'the cyclone type of separatorfor separating finely divided suspended particles from a fluid stream.

More particularly, the invention ;is concerned 'with a device for theimproved separation ofsuspended particles from a fluid streamlay-providing for successive separations in a'plurality of stages.

In the cyclone type of separator the gases with their entrained solidsare introduced into the device a manner that imparts a spiral orswirling motion to them. The resulting centrifugal action causes thesolid particles to be thrown to the outer wall of the cyclone and theyare then allowed to slide down the wall into a collecting hopper. Thepurifiedgas stream is then removed from the separator by suitable means.

Cyclone separators are particularly adapted for removing finely dividedsolids or dust from gas or vapor streams. Thus they find use in thepurification of air in any-industrial installation where considerabledust is formed. A particularly use- 'ful application of thesedevices isin connection with organic reactions employing the fluidized catalysttechnique, as for example, the catalytic treatment of petroleumfractionsin cracking operations, hydroforming and :the like, thesynthesis of hydrocarbonsby reaction of carbon monoxide with'hydrogen,and other reactions of this type. Enormous amountsofcatalyst are handledin catalytic units-employing the fluidized catalyst technique and it isnecessary to-separate suspended or entrained particles of catalyst fromexit gas streams so that this catalystrnay be returned to the processingzone'with a minimum amount of catalystbeing lost. Even a smallpercentage loss from a large plant can amount to several tons ofcatalyst being lost fromthe unit perday. Most of this loss occurs asfine-dust that cannot be separ'ated'efiiciently when conventionalcyclones are employed for the recovery of catalyst.

One object of'the present inventionxis to. provide a means forminimizing the loss of fine particlesof catalyst from equipment'when'the fluidized solids technique is employed. More generally theobjector the present invention is to improve'cyclone separating meansfor the separa-, tion of gases from solids suspended therein whereby amore eficient separation of veryfine particles of solid-material can beeffected.

Other objects of the invention will appear from the followingdescription and from thedrawings.

Figure 1 is a vertical axial section'througha cyclone separator of thepresentginvention.

Figure '2 is a transverse-cross "section taken substantially along theline 2-2 ofFigurefl, looking downward.

Figure. 3 is another transverse .cross section ,of the apparatus shownin Figure 1, taken substantially along theline 3-3 of said figure.

"Figure 4 is a top view of the same apparatus, taken substantially alongthe'line'4--4,Eigure1 1.

Figure 5 is a vertical section of another modification of the invention,being generallysimilar to Figure. 1.

Figure 6 is a transverse section of theapparatus shown in Figure 5,taken substantially alongthe line 66 of'Figure 5and looking-downward.

Figure 7 is a vertical sectional View, of afurther modified form of theinvention.

Figure 8 is a transverse sectionalview; of the apparatus of Figure 7,-t'aken substantiallyalon the line 8--8 of Figure 7;

Figure 9 is a-vertical sectional view'ofanother modified form ofapparatus. g

Figure 10 is a vertical sectional v-iew of" still another modificationof the invention. q

Referring now tothe drawings-particularly Figures 1 to 4,-inclusive, thecyclone-separator as representedconsists of an outer cylindrical casing-I having a-cover orupper end-closure 2 and an inner cylindricaloutlettube- 4, said casing-and said outlet tube-being co-axiallydisposed and thus forming between them-the-annularseparation chamber 6."Positioned at ornear the-top of the cylindrical casing is a gasandsolidsirflet 3-which-is so placed'that it will dischargethe gasmixture more or less tangentially intoannular space- 6. Thisarrangement-sets up a rapidrotation of the gases which-contain thesolids to-be separated.

Alsopositioned within thecasing-is- -an-'-inner cylindrical shell 5which is of-sma11er diameter than the casing I but of largerdiameterthanthe outlet tube 4. Shell 5' is preferably so arranged as to be aboutmidway between the elements" I and 4. Preferably, the inside surfa'ceofinner shell 5 may be highly polished or chromium plated inorder that theseparationof fine-particlesirom 45 the gas stream may be additionallyenhanced. Inner shell" 5 --may be -supported-position by means of---radially disposed ribs or rods suitably positioned as indicatedbynumeral 1 6 or'- by any other effective means.

Attached to the lower portion of the intermediate shell 5 are aplurality f-downwardly directed trough-like chutes i 4 which dischargeinto the lower space l2 of the cyclone. ln lie of chutes; hollow tubesmay be-used desiredQHSee Figures 5," 7-, and 10. That-portion-of' thebottom 3 of the inner shell which connects with the upper ends of thechute entrances is preferably flared so that the solids collected willbe guided into the chute or tube openings. Between adjacent chutes (ortubes) the member 5 has an inturned lip and is notched upwardly so as toappear more or less inverted V-shaped. This modification is desirable inorder to aid in directing the fine particles into the chutes or tubesl4. Also, it is preferred that the elements M be slightly twisted orspiraled with respect to the axis of the cyclone so that the gasespassing through them will be given some degree of spiral rotation to aidfurther in the separation of solid particles. .Preferably, also, themembers l4 flare outwardly toward the inner wall of casing I so thatsolids falling from chutes M will join those sliding down the innersurface of the casing I.

For greater efficiency, the cyclone may be fitted with one or more highvelocity jets 1 which enter annular space to tangentially. Only one jet1 isshown but two or more may be used. Air, steam or other gas will beintroduced through these jets to impart additional rotational velocityto that part of the gas stream that carries the very fine material. Thisfurther facilitates separation of the extremely fine particles which aremost difficult to separate.

The lower end of outer casing I may be joined to a frustro-conicalmember 8, the bottom of which opens into discharge pipe 9. Thisportionof the cyclone structure does not constitute an essential featureof the invention however, and the bottom space l2 of the cyclone may, ifdesired, be just simply constructed by a continuation of the verticalsides of easing 1 instead of using frustro-conical section 8 shown inFigure 1. The tapered section has the advantage, of converging thesolids to a central collecting point, at the sacrifice of somefrictional hold-up.

The length of the inner shell 5 is so chosen that its upper portionterminates at a level below the tangential fluid inlet 3, and the lengthof the outlet tube 4 issuch that its lower opening is about at or evenslightly below the level of the upper openings of troughs or tubes l4.

As a result, there is formed in the upper portion of the cyclone theannular'space 6, previously mentioned, between the outer shell I andoutlet tube 4 extending axially of the separator for a substantialdistance. Below the upper edge of inner shell 5 there are thus formedtwo annular spaces. One, designated by the numeral II, is formed betweenouter casing l and inner shell 5. The other annular space, designated bythe numeral I0, is formed between the inner shell 5 and the outlet tube4. Direct communication exists between the inner annular space [0 andthe upper openings of the tubes or chutes [4, as previously indicated. gY

In the operation of the cyclone the gas or vapor carrying finely dividedsolid particles which are to be separated therefrom is introduced tan!gentially into the annular space 6. .The body of gasentering the cycloneis thus given a spiral motion which causes suspended solid particles tobe thrown against the inside surface of casing I. The separatedparticles then fall down through the annular space H into lower space H.of the cyclone. As the gas proceeds downwardly through the cyclone, thegas nearer the center of the apparatus, which contains the finerparticles, tends to pass down through the inner annular space It; Whenhigh velocity the main stream of falling solids.

jets 1 are employed and gas is introduced through these jets, the spiralmotion of the gas within the inner passage is given additional force andvelocity. Further separation of solid particles from the gas thus takesplace in an nular space I0 and the particles which are sep arated falldown through this annular space and then through the chutes or tubes l4into Any residual particles still remaining suspended in the gas passingthrough the space 10 are removed as the gas proceeds down through thechutes or tubes l6. This results from the rotational twist given thegases by the chutes I4. The gas continues to rotate in a spiral motionas it goes through the tubes. Both the large and the small particleswhich are separated from the gas are removed from the cyclone throughoutlet 9. The gas from which the particles have been separated fiowsinwardly and upwardly and finally is removed from the cyclone throughgas outlet 4.

Figure 1 illustrates also an additional feature of construction forintroducing gasor other fluid through jets into the annular space ID. Ajacket or cylinder 24 is placed aroundoutlet tube 4 so as to provide anannular passage for fluid, gas or liquid, which is supplied to thepassage through a pipe 25. The bottom of this jacket 24 is fitted with ahollow annulus or ring in which are fitted a plurality of tangentiallydirected jets 21 through which air, steam, or other gas or fluid canthen be introduced into annular space It in the same manner as is donewith the-high velocity jets 'l in Figure 1. Gas or other fluid to be fedthrough these jets is introduced into the annular space between outlettube 4 and jacket 24 through inlet pipe 25. If desired, the jets I maybe omitted, but it is frequently desirable to. employ both jets l and2]. It will sometimes be found advantageous to introduce a liquid ratherthan a gas through the jets 1 or jets 21 in Figures 1 and 3.Theadvantage thus obtained is that the fine particles will be wet by theliquid and this will greatly enhance the separation of the particlesfrom the gas stream. Another advantage is that when liquid is introducedrather than a gas through the jets more rotational energy can be addedto the gas stream for the amount of fluid introduced because of thesmaller volume-to-weight ratio of a liquid as compared to a gas.

As previously suggested, it may not be necessary to use both sets ofjets l and 21, especially if a liquid is injected through one set or theother. It may be found advantageous to inject gas through one set andliquid through the other in some cases, as where the solids areparticularly diiflcult to separate.

Although some types of cyclone separators equipped with concentric wallshave been employed prior to the present invention, certain novelfeatures are involved herein which have never heretofore been disclosed.Onev of these features is the provision for the introduction of a highvelocity jet of gas into the inner cylinder in order to impartadditional rotational velocity to that part of the gas stream carryingthe fine material, thus making more eflicient use of the auxiliary jet.Another very important feature is the use of chutes or tubes to carryseparated fine material from the zone of high gas velocity to a zone inwhich there is little or no gas velocity. A very important advantagethus obtained is that the flow of fine material accrues:

out; of the. ;bottom ofthe separator is not: diSe.

forgexample through the outlet tube..4 of. Fig-,

ures 1 to 4.

Still another feature istheprovisionsof chute members such as I4 havingaslight rotational twist or helical arrangement in order to provide/forstill greater efficiency in separating very fine particles from the gasstream.

Figures 5 and 6 illustrate another embodiment of the invention whereinthe outer shell and the feed pipes bear the same reference characters asin-Figures 1 to 4. The annular inner shell element 35, corresponding toelement 5 of Figures 1 to 4, is continued well below the exit port 36,which is the lower end of tube 34, corresponding to tube 4 of Figure 1.In this form of the.invention, an inner conical or frusto-conicalelement 31 is built within allower converging part 38 of shell 35, beingconnected therewith by elements 39 which surround and. define triangularopenings 40. For eXample,-the.-e1ements 35 and 31 may be formed of sheetmetal and the openings 39 formed by forcing metal of the inner element3T-outwardly and metal of-outer element'35 inwardly, the parts beingsuitably secured'together by welding or the like.- As a result, a seriesof tubes extend downwardly from an annular space '42 to a small annularspace 43 at the'bottom of members 35 and 31.

It will be understood that With the construction shown in Figures 5 and6, gases containing solids are admitted through conduit 3 into the mainseparating zone 6. Due to the tangential disposition of feed pipe orconduit 3, the gases are given a rapid rotary motion, as previouslydescribed, and the major portion of the solids separate against theouter wall I. The inner gases descend inside the annular member 35 wheretheir rotation is greatly accelerated by tangential jets of fluid (gas,vapor, or liquid,'preferably the latter, where the fine solids areparticularly difficult to separate). These tangential jets emerge fromthe annular tube 24, fed by a pipe or conduit 25, through tangentiallyarranged nozzle elements 45.

The rapidly rotating and descending gases within the annular member 35lose velocity and flow inwardly and upwardly after passing the lower end35 of gas exit tube 34. The separated solids, however, fall into theannular passage 42 and descend through tubes 41. Gases outside of member35 pass inwardly and upwardly through the openings 40. In so doing, theyare completely separated from the fine solid particles within tubes 4|so the latter are not picked up but continue to fall through annularpassage 43 into the converging body of catalyst which falls along theinner surface of outer wall I of the separator. The flow of gasesthrough the openings is indicated at 44 by the arrows, Figure 5.

Figures '7 and 8 show still another construction modification where anannular trough 5! is provided within the inner shell 50, whichcorresponds to shells 5 and 35 previously described. This trough isbuilt with a plurality of tubes 52 appropriately attached thereto orformed integrally therewith. The fine solid particles descending insidethe wall 50 fall into trough 5| and descend through the tubes 52 to jointhe main body of catalyst at the bottom.

The modification of Figures 7 and 8 may also include a different type ofmeans for increasing rotational velocity. Such means is shown at 53 and54 as inclined vanes in the outer and inner o annular assages. throughthese vanes are given additional. rotary momentumto further facilitatethe separation of-solids. Ifdesired, jets-such as I or 2'1, Figure: 1,orjets 45, Figure 5, may be used in addition to the vanes 53 and 54. Thevanes may be ar*- ranged so that horizontal elements thereof arearrangedeither radially or tangentially, but thelatter is preferable as it tends'to throw the solids to the outside.

A still further modification is shown in Figure 9 which is like Figure 5except-that the outerele-.

ment-58of the inner separator wall, corresponding to element 38 ofFigure 5, is continued down-e wardly by a hollow frusto-conicalextension :59'

and a tubular extension. 60 which ispreferably:

butnotnecessarily cylindrical in shape. By thismeans the fine solidswhich separate inthei'inner zone maybe separated from the coarser'solidswhich separatein the outer zone. They'maybe conveyed to separate storagebins or separate elements of a circulatory system if this is desired.The inner member 31 and the openings 40 are arranged as in Figure 5.

Figure 10 shows a modification of the apparatus of Figure 1 wherein thechutes 14, corresponding,

to..chutes I4 of Figure 1, are spiraled extensively. The angle andextentaof.spiralingshould besuch that the chutes 14 are not whipped byeddy currents which would remove or entrap any of the solids which areflowing down chutes 14. Other elements may be arranged either as inFigures 1 to 4 or as in Figure 5 or Figure 7 and therefore a detaileddescription is not necessary.

It will be understood that the essence of the invention is the apparatusand method for bringing a stream of fluid, especially a gas stream, intoa down-flowing separating zone of generally circular cross section,imparting a strong rotary movement to said stream to separate most ofthe solids against the outer wall of the casing while forcing thelighter fluid portions (i. e., the part containing the most finelydivided solids) to the central zone. This inner or more central part ofthe stream is passed downwardly through the inner shell and given a verysubstantial angular or rotary acceleration, preferably by jet means, asin Figure 1, although the vanes of Figure 7 may suflice. This separatesthe very fine solids which are carried in conduits, either chutes ortubes, to a receiver, while the fluid stream outside the inner shellpasses centrally to the exit without picking up or otherwise interferingwith the stream of fine particles which has been separated from theinner stream.

Although the above description discloses what is believed to be apreferred and practical embodiment of this invention, it will beunderstood by those skilled in the art that the specific details ofconstruction and the arrangement of parts as shown are largely by way ofexample and are not to be construed as limiting the scope of theinvention in any manner.

What is claimed is:

1. A cyclone separator for separating finely divided solid particlesfrom gaseous fluids comprising an outer casing of circular crosssection, a tangential inlet in the upper portion of said casing for theintroduction of the gaseous fluids containing the solid particles, anoutlet tube 00- axially disposed within said casing extending from thelower portion of said casing through the top thereof for the removal ofgaseous fluid from the casing, a coaxially disposed inner cylindricalshell spaced substantially midway between said The descendinggasesaipassing;

7 casing and said outlet tube, the upper end of said inner cylindricalshell terminating at a level below the tangential inlet, the lower endofsaid innerv cylindrical shell terminating at about the lower end ofsaid outlet tube, a plurality of spaced conduit members attached to thelower end of said inner cylindrical shell extending downwardly into thelower portion of the cyclone separator, said inner cylindrical shelldividing the stream of gaseous fluids containing solids into two parts,one part flowing spirally downward between said inner shell and saidcasing thence between said spaced conduit members to the outlet tube andthe other part flowing spirally downward through the annular passagewaybetween the inner shell and the outlet tube and thence into the outlettube, nozzle means arranged adjacent the upper endof said innercylindrical shell positioned to discharge a stream of fluid at highvelocity tangentially into said inner shell to increase the rotationalvelocity of the gaseous stream passing through the annular passagewaybetween the said inner cylindrical shell and the said outlet tube and anoutlet in the bottom of said outer casing for the withdrawal ofseparated solid a particles. 1 a

. 2. A cyclone separator according to claim 1 in which the lower end ofthe inner shell between 8 said conduit members is turned inwardly andupwardly to form an inverted V-shaped lip between adjacent conduitmembers for directing separated particles into said conduits.

3. A cyclone separator according to claim 1 in which the spaced conduitmembers attached to the lower end of said inner cylindrical shell memberextend spirally downward into the lower portion of the cycloneseparator.

- BRADFORD E. BAILEY.

REFERENCES CITED The following references are of record in the file ofthis patent UNITED STATES PATENTS

1. A CYCLONE SEPARATOR FOR SEPARATING FINELY DIVIDED SOLID PARTICLESFROM GASEOUS FLUIDS COMPRISING AN OUTER CASING OF CIRCULAR CROSSSECTION, A TANGENTIAL INLET IN THE UPPER PORTION OF SAID CASING FOR THEINTRODUCTION OF THE GASEOUS FLUIDS CONTAINING THE SOLID PARTICLES, ANOUTLET TUBE COAXIALLY DISPOSED WITHIN SAID CASING EXTENDING FROM THELOWER PORTION OF SAID CASING THROUGH THE TOP THEREOF FOR THE REMOVAL OFGASEOUS FLUID FROM THE CASING, A COAXIALLY DISPOSED INNER CYLINDRICALSHELL SPACED SUBSTANTIALLY MIDWAY BETWEEN SAID CASING AND SAID OUTLETTUBE, THE UPPER END OF SAID INNER CYCLINDRICAL SHELL TERMINATING AT ALEVEL BELOW THE TANGENTIAL INLET, THE LOWER END OF SAID INNERCYLINDRICAL SHELL TERMINATING AT ABOUT THE LOWER END OF SAID OUTLETTUBE, A PLURALITY OF SPACED CONDUIT MEMBERS ATTACHED TO THE LOWER END OFSAID INNER CYLINDRICAL SHELL EXTENDING DOWNWARDLY INTO THE LOWER PORTIONOF THE CYCLONE SEPARATOR SAID INNER CYLINDRICAL SHELL DIVIDING THESTREAM OF GASEOUS FLUIDS CONTAINING SOLIDS INTO TWO PARTS, ONE PARTFLOWING SPIRALLY DOWNWARD BETWEEN SAID INNER SHELL AND SAID CASINGTHENCE BETWEEN SAID SPACED CONDUIT MEMBERS TO THE OUTLET TUBE AND THEOTHER FLOWING SPIRALLY DOWNWARD THROUGH